creating a map for a field in the class

how do I build a timeTable field?

I currently have:

timeTable = (HourScheduleDefinitionModel[])[];

e.g.

[
  {
  day: '0',
  timeline: [
      { from: '01:00', to: '02:00' },
      { from: '20:00', to: '22:00' }
    ]
  },
  {
    day: '1',
    timeline: [ { from: '01:00', to: '04:00' }, { from: '20:00', to: '21:00' } ]
  }
]

and I want to

timeTable: Map<number, Array<HourScheduleDefinitionModel>>;

e.g.

{
0: [{from: '00:00', to: '23:00'}],
1: [{from:'00:00', to:'10:00'},{from:'14:00', to:'16:00'}]
}

the save button shows it
https://stackblitz.com/edit/angular-ivy-slrmqc?fbclid=IwAR3mZbHjz8TkLUZJI1kd7gsMnaPikdS0eyGzdF17RPYJ70jyHhXMOzW8x3w&file=src%2Fapp%2Fapp.component.ts